Stroke is the third leading cause of death in the United States and the leading cause of disability among adults. Currently, there are roughly 3 million stroke survivors with some sort of neurological impairment with $30 billion each year in health care costs and lost productivity. The goal of the proposed research is to develop and demonstrate the feasibility of a portable and non-invasive diffuse optical tomography (DOT) system for measuring cerebral hemodynamic activity associated with brain function, and to apply it to the study and clinical management of functional recovery in stroke survivors. We aim to (1) develop a DOT system capable of providing and displaying recordings with 32 lasers and 32 detectors in real time (i.e., with a 10 ms temporal resolution); (2) develop a fiber optic probe that can secure a large array of source and detector fibers on the head while minimizing motion artifacts; and (3) test the feasibility of the prototype system for acquiring and displaying functional brain activation data in real time. While the goal of this project is to develop a DOT system for clinical study and management of functional recovery, it will also have utility for the basic science community interested in functional brain imaging and could have important implications for the monitoring of neuronal activity in other clinical populations.